UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLE

Abstract: Unloader device for governed air compressors with one or more cylinders with power saving, basically comprising an unloading valve (1) operates by an actuation piston (2) with a seal valve (3), controlled by a compressor governor valve, unloader ports (4) which allows for air passage to the cavity of the compressor cylinders, an expansion chamber (5) which generates the saving of power, where for the ideal functioning, there is an inlet lamella valve (6) with specific shape, as well as an intake chamber (7) and an exhaust chamber (8) with specific shapes and capacities for each of the cylinders which comprise the compressor.

Description: Descriptive Report of the Patent of Invention of an "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BKAKE SYSTEMS OF AUTOMOTIVE VEHICLE." Description The present report is a detailed description accompanied of elucidative drawings of a new and efficient unloader device, or a pressure unloading valve for governed air compressor with one, two or more pistons, usually utilized in air brake systems for automotive vehicles. Presently it is known of several types of unloader device mechanisms for use in governed air compressors; there are two types currently in use. As following described, they present serious inconvenients. One of these mechanisms known as unloading mechanism is used in a disc-type, or ring, air compressor valve (US 07/278.225), where the opening and closing of the valves is provided through pressure from the unloading mechanism exerted on the disc type valve, which is deformed in the long run, causing serious problems of leakage and inefficiency, as well as reair lineion of the air compressor useful life. In this case when the air compressor has two cylinders or more, there is an unloader device for each of the cylinders, thus embarrassing and raising the project and manufacturing costs of this type of air compressor. The other mechanism is known as unloader device by valve type a lamella (DE P 3904172.7) it is a lamella which slides on a surface of a air compressor valve, opening the unloading holes and functioning as an unloader device on the governed air compressors. However such wrhflnism presents dificulties in manu&cturing because the complicated geometry and high costs. Searching for the solution for these inconvenient problems with the objective of improving sensibly the efficiency, useful life, ecomomized power and the facility of design and manufacturing of a governed air compressor with one or more cylinders, it was designed and developed the unloader device for governed air compressor by air brake systems for automotive vehicles, object of the present report. The proposed unloader device is an optional system for the air compressor due to its specific configuration design where it can be easily fit or in withdrawn ftom the as needed. It has the advantage of being used in both one or two cylinder air compressor and be treated as an unloader device with special configuration that makes it more economic in the consumption of the power required by the engine to move the vehicle. The governed air compressors are the ones whose functioning is controlled by maximum and minimum air compressed pressure preset in the air reservoir. Since the governed air compressors utilized in air brake systems are always at work when the vehicle engine is functioning, and therefore always compressing air and deschaiging it in the reservoir, the system pressure control is provided through a governor valve. Such governor valve is actuated by the detemined minimum and maximum pressures of the air compressed in the reservoir, which in turn acts on the air compressor working m rfiAnism which actuates cn the inlet exhaust valve system, and/or unloading holes through the governor device, thus preventing or not the air compression. The governor device, object of the present report, actuated by the governor valve has the function of providing an opening in the compressor cylinder or cylinders, thus opening a valve that closes the unloading holes leaving the air compressor without effect momently. To illustrate and improve the understanding of the present descriptive report, we refer to the figures enclosed. FIGURE 1. Shows the top part in vertical cut of a two-piston air compressor with details of the actuation piston assembly of both valve and device unloadings: FIGURE 2. Shows the air compressor valves support plate with inlet lamella valves , the unloading valve in fan shape and the actuation piston seal valve. It can be seen that one is open and the other is closed, and that two shown valves work simultaneously in the same way. FIGURE 3. Shows a transversal top cut of the air compressor chambers with details of the specific shape of the inlet, exhaust and expansion chambers. FIGURE 4. Shows the cut A-A' of Fig.2, presenting the configuration of the exhaust valve, the support plate of the inlet, seal and unloading valves and the air compressor c__an__bers. FIGURE 5. Shows the inlet lamella valve, the unloading lamella valve and the seal lamella valve of the actuation piston with all shape and configuration details. The unloader device described herein can be utilized for air compressors with one or more cylinders. For better understanding of its functioning, the description here to will be provied in for two- cylinder air compressor. The unloader and power saving device (D), object of the present patent, is basically comprised of an unloading valve (1), actuated by an actuation piston (2) with a seal valve (3), controlled by the air compressor governor valve, unloading ports (4), which allow the air passage to the air compressor cylinders cavity of the air compressor, an expansion chamber (5), which generates the power saving, where for its ideal functioning exists an inlet lamella valve (6) with specific shape, as well as an intake chamber (7) and an exhaust chamber (8) with shape and specific capacities for each cylinder of the air compressor. The unloader device (D) serves to provide the passage from the pumping phase to the empty phase for air compressors used in air brake systems of automotive vehicles which functions as follows: The actuation piston (2) works through preset external pressure. The piston is provided with an actuator pin (9) that displaces parallelly to the actuation piston movement when it is actuated by the governor valve. The actuator pin (9) is displaced within a oblong opening (10) situated on the air compressor valve holder plate (11), which is fitted to an another oblong hole (12) corresponding to the unloading valve (1). When the actuator pin (9) is displaced, an angular movement on the unloading valve (1) is produced due to its specific shape in fan (13) thus providing for the overlap of the unloading valve ports (14) and the unloading ports (4), situated on the valve holder plate (11) causing free passage of the air to the expansion chamber (5) which communicates with the cavity of the air compressor cylinder, which in turn has the function of saving the engine power of the vehicle. With the air compressor working in empty condition, that is, with the unloader device (D) actuated, the air which passes through the unloading ports (4) and enters the expansion chamber (5) generates internal pressure in this chamber. Thus the unloader device (D) admits air in the expansion chamber up to the moment when there is not any exhaustion generated by the air compressor. At this point, one of the expansion chambers generates pressure in the corresponding air compressor cylinder cavity when the later is in upstroke position, and in counterbalance the other side the pressure generated in the other expasion chamber passes to the other cavity of the other air compressor cylinder which is in the downstroke phase, thus helping the cylinder movement and so alternately the pressure generated in the expasion chambers (5) facilitates the moving of the air compressor cylinders saving power of the vehicle engine. When the air compressor has two cylinders there is two chambers of exhaust (5) which week are independently of one another, one corresponding the each air compressor cylinder. With the use of in the unloader device (D), these chambers do not depend on any agent or auxϋiar valve to fulfill the function of saving power. The αMmnunication between the two actuating pistons (2) (one for each air compressor cylinder) of the unloader device (D) is provided throuhg an air line (15) provided by an undercut on the face of the air compressor head to actuate both actuation pistons (2) simultaneously, with their movement in opposite direction, moving the unloading valve (1) always in the same way that is, the two valve open and close at the same time when the actuation pistons (2) are operated by the preset pressure of the air compressor. The return of the actuation pistons (2) for the closing of the unloading valves (1) is provided by a spring (24) which distends when the preset pneumatic signal of the governor valve, which operates the actuation pistons (2) is withdrawn. The unloader device is provided by a seal valve (3) of the actuation piston (2) whose function is it prevent the air compressed by the piston from entering t__ffi c-Mr__bgwl-ere the actuation piirtcm (2) of the unloading valve (1) is housed, causing loss of efficiency of the air compressor fimctioning. Such pressure still exerts force on the actuation piston (2) against the actuator pin (9), which can cause its own deformation. Such seal valve (3) has a specifie shape according to Fig.5 with a circular hole (26) for fitting and placing of the actuator pin (9) of the actuation piston (2), and it presents an extension of the open oblong hole (27) for fitting to the unloading valve axle (1) through the pin (18) with an angular movement accompanying the unloading valve movement and sealing the oblong hole (10) of the actuating pin (9). The unloading valve (1) of the unloader device (D) has the shape of a fan (13), presenting oblong breakthough holes (14) whose opening overlaps the oblong holes or unloading ports (4) located on the air compressor valve holder plate (11), providing for the communication with the expansion chamber (5), and with another oblong hole (16) for pivoting of the actuator pin (9) connected to the actuator pin (2). Such oblong holes (16) is situated at the bottom part of the fan (17) of the unloading valve (1). The oblong holes (10, 16) allow for the angular displacement of the unloading valve (1) on a fixed axle. The unloading valve (1) when operated presents an angular movement with an axle of fixed turn by a pin (18) located between the shape of a fan (13) and the extension of the fan (17) until the fitting of the actuator pin (9) of the actuation piston (2). The fixed pin (18) allows for the angular displacement of the unloading of valve (1) according to the displacement of the actuator pin (9) on the corresponding oblong hole (10, 16) so as to open and close the unloading valve (1) to anti-clock or clockwise movement. For the ideal working of the unloader device (D), object of the present patent, the inlet lamella valve (6) has the specifiec shape of "a cat face" according to Fig.5, being punched out in its central part (19) allowing for air penetration to the intake chamber (7) through the opening of the inlet holes (20) by pressure difference. These holes are arranged in arc side by side, that is, following a semi-circular line (21) on the air compressor valve holder plate (11). Due to the shape of the inlet lamella valve (6) the exhaust valve holes (23) are not covered by the inlet valve (6), thus providing for a simple exhaust valve (22) of with its corresponding exhaust hole (23). Due to the specific configurations for the unloading valve (1) and for the inlet lamella valve (6), and the normal configuration of the exhaust valve (22), the exhaust (8), inlet (7) and expansion (5) chambers, also have specific shapes shown in horizontal cut in Fig.3, so as to obtain a perfect configurations combination in the arrangement and overlapping of the valve holder plate (11) comprising the valves with the conesponding chambers, obtaining therefore the desired fim ioning of the unloader device (D) and also of the governed air compressor as a whole and with considerable saving of power for better efficiency. Therefore, according to the characteristcs of functioning, configuration^ funcrtionability and novelty presented herein, the "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLE", deserves the privilege of a PATENT OF INVENΓΠON."

Claims: CLAIMS 1. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEM OF AUTOMOTIVE VEHICLE", unloader device for governed air compressor with one or more cylinders, with power saving, characterized by comprising an unloading valve (1) moved by an actuation piston (2) with a seal valve (3) controlled by the air compressor governor valve, unloading ports (4) which allow for the passage of air to the cylinder cavities of the air compressor, an expansion chamber (5) which generates the power saving, where for ideal functioning exists a lamella inlet valve (6) with specific shape, as well as an intake chamber (7) and an exhaust chamber (8) with specific shape and capacities, for each one of the cylinders which comprises the air compressor, functioning as follows: the actuation piston (2) operates through preset external pressure. Such piston comprises an actuator pin (9) which displaces parallelly to the movement of the actuation piston (2) when operated; the actuator pin (9) is displaced within a oblong opening (10) located on the valve holder plate of the air compressor (11) which is fitted to another oblong hole (16) corresponding to the unloading valve (1). When the actuator pin (9) is displaced it produces an angular movement on the unloading valve (1) due to its specifie fan shape (13), thus causing the overlap of the unloading valve holes (14) and the unloadeing holes (4), located on the valve holder plate (11) allowing for the free passage of air to the expansion chamber (5) that communicates with the cavity of the air compressor cylinder, and have the function of power saving of the vehicle engine, where the expansion chambers (5) are independent from each other, one corresponding to each air compressor cylinder, and not depending on any agent or auxiliar valve to fulfill the function of saving power. 2. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders, with power saving, according to claim 1, characterized by having the communication between the two actuation pistons (2) (one for each air compressor cylinder) of the unloader device (D), to be through an air line (15) provided by an undercut on the face of the air compressor head, so as to operate the two actuation pistons (2) simultaneously, with the movement in opposite directions, moving the unloading valves (1) always in the same way, that is, the unloading valves open and close at the same time when the actuation pistons (2) are actuated by the preset pressure of the air compressor govemer. 3. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders with power saving, according to claim 1, characterized by the return of the actuation pistons (2) to close the unloading valves (1) be provided by a spring (24), which distends when the preset pneumatic signal of the governor valve which actuates the actuation pistons (2), is withdrawn 4. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders with power saving, according to claim 1, characterized by the unloading valve (1) of the unloader device (D), present a specific fen shape, with break through oblong holes (14) which through their opening overlap the said oblong holes, or unloading ports (4), located on the valve holder plate of the compressor (11), providing the communication with the expansion chambers (5) and to have another oblong hole (16), where the actuator pin (9) is placed connected to the actuation piston (2). With such oblong hole (16) placed on the bottom extension of the fan (17) of the unloading valve (1), allowing the angular displacement of the unloading valve (1) on an axle of fixed turn, by an axle pin (18) situated between the fan shape (13) and the fan extension (17) until the fit of the actuation pin (9) of the actuation piston (2); with the axle pin allowing for the angular displacement of the unloading valve (1) according to the displacement of the actuation pin (9) on the corresponding oblong holes (10, 16), so as to open and to close the unloading valve (1) with anti-clockwise / or clockwise movement 5. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders with power saving, according to claim 1, characterized by the inlet valve lamella (6) possessing a specifc shape of "cat face" (25), according to Fig.5, be punched out in the central area (19) allowing for the passage of air to the intake chamber (7) through the opening of the inlet ports by difference of pressure. Theseports are arranged side by side in form of arc, that is, following a semi-circular time (21), located on the valve holder plate of the compressor (11) where the exhaust valve holes (23) are not covered by the inlet valve (6) so having an simple exhaust valve with its corresponding exhaust holes (23). 6. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders with power saving, according to claim 1, characterized by the seal valve (3) of the actuation pistons (2), having a specific shape according to fig.5 with a circular hole (26) for fitting and placement of the actuation pin (9), presenting an extesion with an open oblong hole (27) for fitting to the fixed axle of the unloading valve (1) through the pin (18), having an angular movement which accompanies the movement of the unloading valve, sealing the oblong hole (10) of the actuation pin (9), with the function of preventing the air compressed by the piston from entering the chamber where the actuation piston is housed (2), what causes loss of efficiency of the functioning of the compressor and force on the actuation piston (2) against the actuation pin (9). 7. "UNLOADER DEVICE FOR GOVERNED COMPRESSOR FOR AIR BRAKE SYSTEMS OF AUTOMOTIVE VEHICLES", unloader device for governed air compressor with one or more cylinders with power saving, according to claim 1, characterized by the exhaust (8), inlet (7) and expansion chambers (5), possess specific shape as shown in horizontal cut in Fig.3, so as to obtain a perfect configurations combination on the positioning and overlapping of the valves holder plate (11) comprising the valves and their corresponding chambers, obtaining the desired functioning of the unloader device (D) and the compressor governing with considerable saving of power.

Inventors: DOS SANTOS CARLOS ROBERTO, DOS SANTOS JARBAS, RANIERI JOSE ANTONIO, DOS SANTOS, CARLOS, ROBERTO, DOS SANTOS, JARBAS, RANIERI, JOSE, ANTONIO
Applicants: FREIOS VARGA SA, FREIOS VARGA S/A
Application year: 1994
Main classification: F04B49
IPC codes: F04B39, F04B49